CN108988547B

CN108988547B - Stator and motor

Info

Publication number: CN108988547B
Application number: CN201810525599.9A
Authority: CN
Inventors: 长泽纯
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2017-05-31
Filing date: 2018-05-28
Publication date: 2020-09-18
Anticipated expiration: 2038-05-28
Also published as: US20190157917A1; EP3410576A1; CN108988547A; EP3410576B1; US10734849B2; JP2018207604A

Abstract

The invention provides a stator and a motor. The upper insulator and the lower insulator each have an enlarged portion that expands in the circumferential direction near the radially outer tip of the tooth, and the upper insulator and the lower insulator are wound around the tooth to form a coil.

Description

Stator and motor

Technical Field

The invention relates to a stator and a motor.

Background

Japanese laid-open patent publication No. 2009-95233 discloses an example of a stator for an electric motor. The stator disclosed in japanese laid-open patent publication No. 2009-95233 is configured by winding a driving coil around a stator core having a plurality of choke coils with an insulator made of an insulating material interposed therebetween. A drive coil is wound around the teeth of each stator core via insulators.

A pole piece portion extending in the rotational direction of the magnet rotor is disposed at the tip end of the pole tooth. A flange portion for preventing the drive coil from collapsing toward the magnet rotor is provided on the insulator of the pole piece portion. The corner of the convex edge part is in a circular arc shape. An arc portion having a large curvature is formed at one diagonal corner portion of the bead portion, and an arc portion having a small curvature is formed at the other diagonal corner portion.

According to such a configuration, the moment when the coiled wire spinneret is transferred from the linear track to the circular track is increased by the circular arc portion having a large curvature, and the gap between the driving coil and the insulator is reduced, thereby reducing the height of the coil terminal protruding in the axial direction from the stator core.

However, in the case of manufacturing the stator of japanese laid-open patent publication No. 2009-95233, when the insulators are divided in the direction of the rotation axis of the magnet rotor, in the step of winding the lead wire to form the drive coil, there is a possibility that the lead wire is caught by the fitting portion of the divided insulator, and productivity is lowered.

Disclosure of Invention

In view of the above circumstances, an object of the present invention is to provide a stator capable of improving productivity.

An exemplary embodiment of the present invention includes: a stator core having an annular core back centered on a central axis extending in a vertical direction; an upper insulator disposed on an upper side of the stator core; and a lower insulator disposed below the stator core. The stator core includes: a plurality of teeth radially protruding from the core back; and an umbrella portion extending from a radial tip portion of the tooth in a circumferential direction. The upper insulator covers at least a portion of an upper surface of the tooth. The lower insulator covers at least a portion of a lower surface of the tooth. The upper insulator and the lower insulator each have an enlarged portion that expands in the circumferential direction in the vicinity of the radially outer tip of the tooth. A wire is wound around the teeth via the upper insulator and the lower insulator to form a coil. The enlarged portion of the lower insulator has a guide portion formed on an upper outer edge thereof in a circumferential direction outside a vicinity of a region where the lead wire is wound from an upper side to a lower side.

A motor according to an exemplary embodiment of the present invention includes the stator and a rotor disposed radially outward or radially inward of the stator and rotatable with respect to the stator.

According to the stator of the exemplary embodiment of the present invention, productivity can be improved.

According to the motor of the exemplary embodiment of the present invention, productivity of the stator provided in the motor can be improved, and thus productivity of the motor can be improved.

The above and other features, elements, steps, features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 is a perspective view of an axial flow fan according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a state where the impeller is detached from the axial fan.

Fig. 3 is a partial longitudinal sectional perspective view of an axial flow fan according to an embodiment of the present invention.

Fig. 4 is a perspective view of a motor provided in the axial flow fan.

Fig. 5 is a perspective view of a stator according to an embodiment of the present invention.

Fig. 6A, 6B, and 6C are perspective views showing a partial structure in a state where the stator is exploded.

Fig. 7 is an enlarged view of a main portion of the stator.

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the following description, the direction in which the central axis C1 extends is referred to as the "vertical direction". The radial direction about the center axis C1 is simply referred to as the "radial direction", and the circumferential direction about the center axis C1 is simply referred to as the "circumferential direction". However, the vertical direction does not indicate the positional relationship and direction when the device is actually mounted. In each drawing, the upper side is denoted by X1, and the lower side is denoted by X2.

< 1. integral structure of axial fan >

First, the overall structure of an axial flow fan according to an embodiment of the present invention will be described. Fig. 1 is a perspective view of an axial flow fan 50 according to an embodiment of the present invention. Fig. 2 is a perspective view showing a state where impeller 1 is removed from axial flow fan 50. Fig. 3 is a partial longitudinal sectional perspective view of the axial flow fan 50. Fig. 4 is a perspective view of the motor 2 provided in the axial flow fan 50.

The axial flow fan 50 includes an impeller 1, a motor 2, a motor base portion 3, a casing 4, and ribs 5.

The motor base portion 3, the housing 4, and the ribs 5 are formed of a resin material as the same member. The casing 4 accommodates the impeller 1 and the motor 2 therein, and is disposed radially outward of the impeller 1 and the motor 2.

The motor 2 rotationally drives the impeller 1 about a central axis C1. The motor 2 includes a bearing 21, an oil retaining felt 22, a sheet holder 23, an MG sheet 24 (magnetic sheet), a washer 25, a shaft 26, a stator 27, a rotor 28, and a circuit board 29.

The motor base portion 3 is coupled to the housing 4 at four circumferential portions by ribs 5, and supports the motor 2. The motor base portion 3 has a base portion 31 expanding in the radial direction on the lower surface side and a bearing holding portion 32 protruding upward from the central portion of the base plate 31.

The bearing holding portion 32 holds the bearing portion 21 therein. The bearing portion 21 is formed of a sleeve bearing. The bearing portion 21 may be formed of a pair of ball bearings arranged vertically.

The bearing holding portion 32 accommodates therein the oil-holding felt 22, the sheet holder 23, the MG sheet 24, and the washer 25 in addition to the bearing portion 21.

The shaft 26 is a columnar member extending in the vertical direction along the center axis C1, and is formed of a metal such as stainless steel, for example. The bearing portion 21 holds the shaft 26 rotatably about the center axis C1.

The stator 27 is disposed radially outward of the bearing holding portion 32 and is fixed to the bearing holding portion 32. The stator 27 has a stator core 271, an upper insulator 272, a lower insulator 273, and a plurality of coils 274. The stator core 271 is formed of laminated steel plates in which electromagnetic steel plates such as silicon steel plates are laminated in the vertical direction. The upper insulator 272 and the lower insulator 273 are made of an insulating resin. The coil 274 is formed by winding a conductive wire in the vertical direction around the stator core 271 with an upper insulator 272 and a lower insulator 273 interposed therebetween. The more detailed structure of the stator 27 will be described later.

A circuit board 29 is disposed below the stator core 271. The circuit board 29 is a board on which a circuit for supplying a drive current to the coil 274 is mounted. The lead lines of the coil 274 are electrically connected to the above-described circuit.

The rotor 28 has a rotor yoke portion 281 and a magnet 282. The rotor yoke portion 281 is a substantially cylindrical member having a top plate portion 281A at the top and opening at the bottom, and is formed of a magnetic material. The top plate 281A has an opening penetrating in the vertical direction. A cylindrical magnet 282 is fixed to an inner peripheral surface of the rotor yoke 281. The magnet 282 is disposed radially outward of the stator 27. The magnetic pole surfaces on the inner circumferential side of the magnet 282 have N poles and S poles alternately arranged in the circumferential direction. A magnetic path is formed between the rotor yoke 281 and the magnet 282, and leakage flux from the magnet 282 to the outside of the axial fan 50 can be reduced.

The impeller 1 has an impeller cup 11 and a plurality of blades 12, and is formed of a resin material. The impeller cup 11 is a substantially cylindrical member having a cover 11A at the top. A shaft 26 is fixed to the cover 11A. A rotor yoke 281 is fixed to the inside of the impeller cup 11. A plurality of blades 12 are formed radially outside the impeller cup 11.

In the axial flow fan 50 having such a configuration, when a drive current is applied to the coil 274 of the stator 27, a magnetic flux in the radial direction is generated in the stator core 271. Then, a circumferential torque is generated in the rotor 28 by the action of the magnetic flux between the stator core 271 and the magnet 282. As a result, the rotating portion constituted by the rotor 28 and the impeller 1 rotates about the central axis C1. The impeller 1 rotates counterclockwise in a plan view.

When the impeller 1 rotates, an airflow is generated by the plurality of blades 12. That is, air can be blown by generating an air flow having the upper side of the axial fan 50 as the air intake side and the lower side as the air exhaust side.

< 2. Structure of stator

Next, the structure of the stator 27 provided in the motor 2 of the present embodiment will be described in more detail. Fig. 5 is a perspective view showing the structure of the stator 27 of the present embodiment. Fig. 6 is a perspective view showing a state in which the stator 27 is disassembled. However, coil 274 is not labeled in FIG. 6. Fig. 6(a) is a perspective view of the upper insulator 272, fig. 6(B) is a perspective view of the stator core 271, and fig. 6(C) is a perspective view of the lower insulator 273.

As shown in fig. 6, the stator core 271 has a core back 2711, a plurality of teeth 2712, and a plurality of umbrella-shaped portions 2713. The core back 2711 is annular about the center axis C1 and is located at the center of the stator core 271.

The plurality of teeth 2712 are configured to radially protrude outward in the radial direction from the outer peripheral surface of the core back 2711. In the present embodiment, the number of teeth 2712 is four as an example. That is, the motor 2 of the present embodiment is a four-slot motor. Umbrella-shaped portion 2713 is configured to extend in the circumferential direction from the radially outer tip of tooth 2712. That is, umbrella-shaped portion 2713 is formed in the same number as teeth 2712.

The upper insulator 272 is disposed above the stator core 271. The upper insulator 272 has a central upper housing portion 2721, a plurality of tooth upper housing portions 2722, and a plurality of enlarged portions 2723.

The central upper cover portion 2721 covers the upper surface and the outer peripheral surface of the core back 2711. The upper tooth cover portions 2722 are configured to radially protrude outward in the radial direction from the central upper cover portion 2721. The tooth upper cover 2722 covers the upper surface and circumferentially opposite side surfaces of the tooth 2712. The number of the teeth upper cover 2722 is the same as the number of the teeth 2712.

The enlarged portion 2723 is configured to circumferentially extend from a radially outer tip portion of the tooth upper cover portion 2722. Enlarged portion 2723 covers the upper surface of umbrella-shaped portion 2713 and the side surface on the core back 2711 side. The enlarged portions 2723 are equal in number to the number of the tooth upper cover portions 2722.

The enlarged portion 2723 includes an enlarged cover portion 2723A, an upper insulator wall portion 2723B, and an auxiliary wall portion 2723C. The enlarged cover portion 2723A is a plate-shaped portion that is formed by enlarging in the circumferential direction from the radially outer tip portion of the upper surface of the tooth upper cover portion 2722.

The upper insulator wall portion 2723B extends in the circumferential direction on both circumferential sides of the tooth upper cover portion 2722, and protrudes downward from the enlarged cover portion 2723A. The auxiliary wall portion 2723C extends in the circumferential direction on both circumferential sides of the tooth upper cover portion 2722, protrudes downward from a radially inner edge portion of the enlarged cover portion 2723A, and is radially inward of the upper insulator wall portion 2723B so as to contact the upper insulator wall portion 2723B. The protruding amount of the auxiliary wall portion 2723C is smaller than the protruding amount of the upper insulator wall portion 2723B.

The lower insulator 273 is disposed below the stator core 271. The lower insulator 273 has a central lower hood portion 2731, a plurality of tooth lower hood portions 2732, and a plurality of enlarged portions 2733.

The central lower cover portion 2731 covers the lower surface and the outer peripheral surface of the core back 2711. The lower tooth cover portions 2732 are formed to radially protrude outward in the radial direction from the central lower cover portion 2731. Lower tooth cover portion 2732 covers the lower surface and circumferentially opposite side surfaces of tooth 2712. The number of teeth lower cover portions 2732 is the same as the number of teeth 2712.

The enlarged portion 2733 is formed to extend in the circumferential direction from the radially outer tip portion of the under-tooth cover portion 2732. Enlarged portion 2733 covers the lower surface of umbrella-shaped portion 2713 and the side surface on the core back 2711 side. The enlarged portions 2733 are formed in the same number as the number of the teeth lower cover portions 2732.

The enlarged portion 2733 includes an enlarged cover portion 2733A, a lower insulator wall 2733B, and an auxiliary wall 2733C. The enlarged cover portion 2733A is a plate-shaped portion formed by enlarging in the circumferential direction from the radially outer tip portion of the lower surface of the under-tooth cover portion 2732.

Lower insulator wall portions 2733B extend circumferentially on both circumferential sides across tooth lower cover portion 2732 and protrude upward from the radially inner edge portion of enlarged cover portion 2733A. The auxiliary wall portion 2733C extends in the circumferential direction on both circumferential sides of the tooth lower cover portion 2732, protrudes upward from the enlarged cover portion 2733A, and contacts the lower insulator wall portion 2733B radially outward of the lower insulator wall portion 2733B. The protruding amount of the auxiliary wall portion 2733C is smaller than the protruding amount of the lower insulator wall portion 2733B.

In a state where the upper insulator 272 is mounted on the upper side of the stator core 271, the enlarged cover portion 2723A contacts a part of the upper surface of the umbrella-shaped portion 2713, and covers the part of the upper surface from above, and the upper insulator wall portion 2723B contacts the surface of the umbrella-shaped portion 2713 on the core back 2711 side.

In a state where lower insulator 273 is mounted on the lower side of stator core 271, enlarged cover portion 2733A contacts a portion of the lower surface of umbrella-shaped portion 2713, covers the lower surface from below, and auxiliary wall portion 2733C contacts the surface of umbrella-shaped portion 2713 on the core back 2711 side.

That is, at least a part of

enlarged portions

2723 and 2733 contacts a surface of umbrella-shaped portion 2713 on the core back 2711 side. Thereby, upper insulator 272 and lower insulator 273 can be firmly fixed to stator core 271.

At least a part of enlarged portion 2723 of upper insulator 272 contacts the upper surface of umbrella 2713, and at least a part of enlarged portion 2733 of lower insulator 273 contacts the lower surface of umbrella 2713. This enables the upper insulator 272 and the lower insulator 273 to be axially positioned.

As described above, the stator 27 is configured by winding the conductive wire to form the coil 274 in a state where the upper insulator 272 and the lower insulator 273 are fixed to the stator core 271. Specifically, the coil 274 is formed by winding a conductive wire in the vertical direction around the upper tooth cover portion 2722 and the lower tooth cover portion 2732. That is, the wire is wound around the tooth 2712 via the upper insulator 272 and the lower insulator 273.

As shown in fig. 5, the coil 274 is formed for each tine 2712, and therefore four coils 274 are formed in the same number as the tines 2712. In fig. 5, a white-bottomed arrow marked at the coil 274 indicates a direction in which the wire is wound.

Fig. 7 is an enlarged view of a main portion typically showing the structure of the upper insulator 272, the lower insulator 273, and the stator core 271 of the coil 274A shown in fig. 5 among the four coils 274. As shown in fig. 7, a guide portion G1 is formed on the outer edge of the lower insulator wall portion 2733B on the outer side and upper side in the circumferential direction. The guide portion G1 is located in the vicinity of a region R1 in which the lead wire is wound from the upper side to the lower side in the coil 274A configured by winding the lead wire in the white arrow direction shown in fig. 5.

As described above, the stator 27 of the present embodiment includes: a stator core 271 having an annular core back 2711 centered on a central axis C1 extending in the vertical direction; an upper insulator 272 disposed on the upper side of the stator core 271; and a lower insulator 273 disposed below the stator core 271. The stator core 271 has a plurality of teeth 2712 projecting in the radial direction from a core back 2711, and an umbrella 2713 extending in the circumferential direction from the radial front end portion of the teeth 2712. The upper insulator 272 covers at least a portion of the upper surface of the tooth 2712, and the lower insulator 273 covers at least a portion of the lower surface of the tooth 2712. The upper insulator 272 and the lower insulator 273 each have enlarged

portions

2723 and 2733 which are circumferentially expanded in the vicinity of the radially outer tip of the tooth 2712, and the coil 274 is formed by winding a wire around the tooth 2712 via the upper insulator 272 and the lower insulator 273, and the guide portion G1 is formed on the outer edge of the enlarged portion 2733 of the lower insulator 273, which is circumferentially outside and above the vicinity of the region R1 where the wire is wound from the upper side to the lower side.

According to such a configuration, when the wire is wound to form the coil 274, even when the wire wound from the upper side to the lower side contacts the enlarged portion 2733, the wire is guided by the guide portion G1 to be separated from the enlarged portion 2733. Therefore, the lead is less likely to be caught by the enlarged portion 2733, and productivity of the stator 27 can be improved.

As shown in fig. 7, the lower insulator wall portion 2733B is disposed radially inward of the upper insulator wall portion 2723B. The lower insulator wall 2733B and the upper insulator wall 2723B face each other with a gap therebetween, and the groove W1 is formed in the gap. In a region R1 (fig. 7) near a region R2 where the lead wire is wound from the lower side to the upper side of the coil 274A shown in fig. 5, the lower insulator wall 2733B does not constitute a guide portion. Therefore, the lower insulator wall 2733B constitutes only the guide portion G1 as a guide portion.

That is, the enlarged portion 2733 of the lower insulator 273 has a lower insulator wall 2733B extending in the circumferential direction and protruding upward, the enlarged portion 2723 of the upper insulator 272 has an upper insulator wall 2723B extending in the circumferential direction and protruding downward, the lower insulator wall 2733B is disposed radially inward of the upper insulator wall 2723B, and the lower insulator wall 2733B and the upper insulator wall 2723B face each other with a gap therebetween, thereby forming the groove W1. The lower insulator wall 2733B includes a guide portion G1 only on the outer edge on the upper side in the circumferential direction in the vicinity of the region where the lead wire is wound from the upper side to the lower side.

In the case where the guide portion G1 is not formed, the lead wire is easily fitted into the groove portion W1 in the vicinity of the region where the lead wire is wound from the upper side to the lower side. However, since the guide portion G1 is configured in the present embodiment, the lead wire is guided by the guide portion G1 to be discharged to the outside of the groove portion W1, and can be separated from the lower insulator wall portion 2733B. On the other hand, in the vicinity of the region where the wire is wound from the lower side to the upper side, the groove portion W1 is formed so as to face the opposite side to the direction in which the wire is wound, and therefore, the wire is difficult to be fitted into the groove portion W1, and therefore, a guide portion for guiding the wire is not necessary. Thus, the guide portion is not formed in the vicinity of the region where the lead wire is wound from the lower side to the upper side, and therefore, the gap between the lower insulator 273 and the upper insulator 272 can be prevented from expanding.

The auxiliary wall portion 2723C of the upper insulator 272 forms an upper insulator corner CR1 extending outward and downward in the circumferential direction in a region axially opposed to the guide portion G1.

That is, the enlarged portion 2723 of the upper insulator 272 has an upper insulator corner CR1 extending circumferentially outward and downward in a region axially facing the guide portion G1. This narrows the gap between the lower insulator 273 and the upper insulator 272, making it difficult for the wire to enter the gap.

Further, an outer end portion of the lower insulator wall portion 2733B on the opposite side to the guide portion G1 in the circumferential direction constitutes a lower insulator corner portion CR2 extending outward and upward in the circumferential direction.

That is, in the enlarged portion 2733 of the lower insulator 273, a lower insulator corner CR2 extending outward and upward in the circumferential direction is formed at the outer end portion on the side opposite to the side where the guide portion G1 is arranged in the circumferential direction. Thus, the gap is narrowed at both sides of the upper and lower insulators in the circumferential direction, and the lead wire can be made difficult to enter the gap.

The upper insulator wall 2723B and the auxiliary wall 2733C axially face each other with a gap S1 therebetween, and the auxiliary wall 2723C and the lower insulator wall 2733B axially face each other with a gap S2 therebetween. That is, the enlarged portion 2723 of the upper insulator 272 and the enlarged portion 2733 of the lower insulator 273 are axially opposed to each other with a gap S2 therebetween.

In the present embodiment, the stator 27 is designed so that the gap S2 is formed so that the stator core 271 is sandwiched in the axial direction by the enlarged portion 2723 of the upper insulator 272 and the enlarged portion 2733 of the lower insulator 273 even when an error occurs in the lamination of the stator core 271. Even when the gap S2 is formed, the guide portion G1 is formed, and therefore, the peripheral elements of the lead wire can be prevented from being caught.

The guide portion G1 has a curved surface that curves smoothly outward and downward in the circumferential direction. This can further suppress the wire from hooking the enlarged portion 2733. The guide portion G1 is not limited to having the curved surface, and may have, for example, an inclined surface that inclines linearly downward as it goes outward in the circumferential direction.

In the above description of fig. 7, the configuration in which the guide portion G1 is provided in the lower insulator wall portion 2733B in the vicinity of the region R1 in which the wire is wound in the downward direction of the coil 274A (fig. 5) has been described, but similarly to the remaining three coils 274, the guide portion G1 is provided in the vicinity of the region in which the wire is wound in the downward direction in the lower insulator wall portion 2733B. That is, as in the lower insulator 273 shown in fig. 6, the guide portions G1 are formed in the portions surrounded by the round marks in the enlarged portions 2733 corresponding to the teeth 2712.

Therefore, the number of the guide portions G1 is equal to the number of the teeth 2712. This can suppress the wire wound around all the teeth 2712 from being caught by the peripheral elements.

The radially inner surfaces of the auxiliary wall 2723C and the lower insulator wall 2733B are curved. That is, the radially inner surfaces of the

enlarged portions

2723 and 2733 are curved. Therefore, the length of the part of the upper insulator and the lower insulator, on which the lead wire is wound, can be increased, and the number of turns of the coil can be increased. That is, the length of the tooth upper cover portions 2722 can be made longer than when the radially inner surfaces of the

enlarged portions

2723 and 2733 linearly extend in a direction orthogonal to the direction in which the tooth upper cover portions 2722 extend, and therefore the space in which the wire is wound is enlarged. However, the radially inner surfaces of the

enlarged portions

2723 and 2733 do not have to be curved.

Here, as shown in fig. 4, in the motor 2, the rotor yoke portion 281 is disposed radially outward of the umbrella-shaped portion 2713. The magnet 282 fixed to the inner peripheral surface of the rotor yoke 281 is disposed radially outward of the umbrella 2713.

That is, the motor 2 of the present embodiment is a so-called outer rotor type, and includes a stator 27 and a rotor 28 disposed radially outward of the stator 27 and rotatable with respect to the stator 27. As described above, the productivity of the stator 27 can be improved, and therefore, the productivity of the motor 2 can be improved.

The umbrella-shaped portion 2713 is disposed radially outward of the core back 2711, and the rotor 28 is disposed radially outward of the umbrella-shaped portion 2713. In such an outer rotor type structure, the

enlarged portions

2723 and 2733 are circumferentially expanded along the umbrella-shaped portion 2713, and even in this case, the guide portion G1 can suppress the wire from being caught by peripheral elements.

< 3. other >)

Although the embodiments of the present invention have been described above, the embodiments can be variously modified and combined within the scope of the present invention.

For example, the present invention can be applied to a so-called inner rotor type motor. In this case, in the stator core, the teeth project radially inward from the annular core back, and extend in the circumferential direction from radially inner tip portions of the teeth to form an umbrella-shaped portion. The rotor is disposed radially inward of the umbrella-shaped portion. The enlarged portions of the upper insulator and the lower insulator are circumferentially expanded along the core back. The enlarged portion of the lower insulator forms a guide portion.

That is, the inner rotor type motor includes a stator and a rotor disposed radially inward of the stator and rotatable with respect to the stator. This can improve productivity of the stator by suppressing hooking of the lead wires to the peripheral elements, and thus can improve productivity of the inner rotor type motor.

The present invention can be suitably applied to, for example, a motor mounted on an axial fan. However, the present invention can also be applied to a centrifugal fan, a diagonal flow fan, and the like.

Claims

1. A stator is provided with:

a stator core having an annular core back centered on a central axis extending in a vertical direction;

an upper insulator disposed on an upper side of the stator core; and

a lower insulator disposed below the stator core,

the stator core includes:

a plurality of teeth radially protruding from the core back; and

an umbrella-shaped portion extending from a radial tip portion of the tooth in a circumferential direction,

the upper insulator covers at least a portion of the upper surface of the tooth,

the lower insulator covers at least a portion of the lower surface of the tooth,

the upper insulator and the lower insulator each have an enlarged portion extending in the circumferential direction in the vicinity of the radially outer tip of the tooth,

a coil is formed by winding a wire around the teeth via the upper insulator and the lower insulator,

the above-described stator is characterized in that,

a guide portion is formed at an outer edge of the enlarged portion of the lower insulator on an outer side and an upper side in a circumferential direction in a side surface region covering the back side of the core of the umbrella-shaped portion,

the guide portion has a curved surface that is curved downward and toward the circumferential outer side.

2. The stator according to claim 1,

the enlarged portion of the lower insulator has a lower insulator wall portion extending in the circumferential direction and projecting upward,

the enlarged portion of the upper insulator has an upper insulator wall portion extending in the circumferential direction and projecting downward,

the lower insulator wall portion is disposed radially inward of the upper insulator wall portion,

the lower insulator wall and the upper insulator wall are opposed to each other with a gap therebetween to form a groove,

the lower insulator wall portion is configured such that the guide portion is formed only on an outer edge of an upper side of the lower insulator wall portion in a circumferential direction in a vicinity of a region where the lead wire is wound from an upper side to a lower side.

3. The stator according to claim 1 or 2,

the enlarged portion of the upper insulator has an upper insulator corner portion extending toward the outer circumferential side and downward in a region axially opposed to the guide portion.

4. The stator according to claim 3,

the enlarged portion of the lower insulator forms a lower insulator corner portion extending outward and upward in the circumferential direction at an outer end portion on a side opposite to the side where the guide portion is arranged in the circumferential direction.

5. The stator according to claim 1 or 2,

the enlarged portion of the upper insulator and the enlarged portion of the lower insulator are opposed to each other with a gap therebetween in the axial direction.

6. The stator according to claim 1 or 2,

the number of the guide parts is equal to the number of the teeth.

7. The stator according to claim 1 or 2,

the guide portion is located at a position overlapping the teeth when viewed in the radial direction.

8. The stator according to claim 1 or 2,

at least a part of the enlarged portion contacts a surface of the umbrella portion on the core back side.

9. The stator according to claim 1 or 2,

at least a part of the enlarged portion of the upper insulator contacts an upper surface of the umbrella portion,

at least a part of the enlarged portion of the lower insulator contacts a lower surface of the umbrella portion.

10. The stator according to claim 1 or 2,

the radially inner surface of the enlarged portion is curved.

11. A motor is characterized by comprising:

a stator as claimed in any one of claims 1 to 10; and

and a rotor disposed radially outward or radially inward of the stator and rotatable with respect to the stator.

12. The motor of claim 11,

the umbrella-shaped portion is disposed radially outward of the core back,

the rotor is disposed radially outward of the umbrella portion.